The long-term goal of the present program of research is to evaluate the performance of the World Health Organization's Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST) for alcohol in the emergency department. Screening and associated interventions for at-risk alcohol users in the emergency department have been a major area of research, in part because the emergency department is an opportunistic environment to screen people who otherwise have limited contact with health care providers. Most research has focused on various treatment interventions, but successful screening is a key precursor to effective treatment. This screening and treatment approach has also been explored for other substances, and a screening tool that evaluates multiple substances simultaneously has the potential to make screening more efficient. However, gains in efficiency may be offset if the tool does not adequately screen for a particular substance. The ASSIST was developed for the primary care setting and its scoring was developed to be consistent across substances for ease of use. Its use in the emergency department has not previously been explored. Additionally, the requirement of consistent scoring across substances may not be optimal for alcohol use and does not allow for differential scoring by sex, which is used in some other alcohol screening tools. The current study will evaluate the alcohol specific subscore of the ASSIST for emergency department patients in three ways. First, in Aim 1 the weighting of the individual questions that comprise the alcohol subscore will be explored to determine if there is evidence that the weighting should be different for alcohol questions as compared to weights for other substances, or if the weighting of alcohol questions should be different for women versus men. Aim 2 will explore whether the established cutoff scores distinguishing moderate- and high-risk use are consistent with the alcohol use and negative consequences experienced by people classified into those groups. Finally, Aim 3 will compare the alcohol use and negative consequences of people grouped into moderate- and high-risk use by the ASSIST to people grouped into similar risk levels by another alcohol screening tool, the Alcohol Use Disorders Identification Test. The proposed project will be carried out using data from four completed federally funded (NIAAA and CDC) clinical trials. This project will contribute to knowledge of how to screen for alcohol use in the emergency department for clinical and research purposes.